Process of diluting acids



J. E. 'EGLESON PRocass-*OF DILUTING ACIDS Filed oct. 16, 1922 w 1J \\|/l r Il lr H /r 0 N /MIZ IIIIII Il 1|- f T f \l E N /Il\ V rr CJ V N M lv 6 E. E W n n MQQw-O KQbQQQ` MN m. mul r\|. w .m P n mv MN. SN. WL .VJ/ H y l, s... ...,I..- V J V u y, I, Q` n e n. u

Sept. 9 1924.

ATTORNEYS which the hot acid comes in contact.

JAMES ERNEST EGLESON, OF RIDLEY PARK, PENNSYLVANIA, ASSIGNOR TO GENERAL CHEMICAL COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK,

PROCESS 0F DIIQUTING ACIDS.

Application filed October 16, 1922.

T 0 all whom it may concern:

Be it known that I, JAMES ERNEST Eo- LEsoN, a citizen of' the United States, and resident of Ridley Park, in the county lof Delaware and State of Pennsylvania, have invented certain new and useful Improvements in Processes of Diluting Acids, of which the following is a specification.

This/invention relates more particularly to the ,art of diluting strong sulfuric acid to acid of a weaker strength and the object of the invention is to conduct the diluting operation in such a manner that injurious effects on the apparatus due to the heat evolved when water or a weak, sulfuric acid is added as a diluent to strong sulfuric acid, are almost entirely avoided.

It is well known that in diluting sulfuric acid considerable heat is evolved and the temperature rise causes the hot diluted acid to produce injurious eifects upon materials of which the apparatus is composed with In the practice as now generally followed, the acid and the water are simultaneously run into a conduit, which in turn dips under the surface of a rather large body of diluted acid of the strength desired, which is subjected to the cooling action of a coolincoil submerged within the body of acid. he cooled acid collects at the bottom and rises through a riser placed at the bot-tom of the container' and running upwardly to a'point somewhat Ahigher than the egress end of'the conduit which delivers strong acid and water to the body of the diluted product. The over-flow from this riser,'which is eected by a goose neck contrivance, then passes on to storage. The low specific thermal capacity of the sulfuric acid, the great amount of heat evolved on mixing and the generally poor conductivity of the material of construction of which the large vessel is built all tend to a very shortened life of the conduit in which the mixing actually takes place and increased wear and tear on the walls of the vessel Where this product has the highest temperature.

The present invention is intended to overcome these defects and disadvantages. The process may be conveniently carried out in the apparatus illustrated in the accompanying drawing. v

The resent invention is based upon the utilization of a cooled body of finished acid Serial No. 594,732.

as an absorbent o" 'he -heat generated on dilution. By introe... zing this cooled body of finished product into the same vessel simultaneously with the strong acid and the product that is diluted acid of the proper strength. Within this vessel A there are cooling coils (not shown) .and in this storage vessel A the capacity for cooled product is about equal to a fifty minutes production of the mixing chamber to be described. Other proportions between the contents of the storage and the production rate of the mixing chamber may, of course, be used, and such change of proportion will necessitate the proper readjustment between the cooling capacity of the coils and the product cooler in each case. Fromthe product cooler A the cooled finished product iiows through the conduit B into the mixing chamber D, circulation being maintained by means of an air-lift, the air being supplied through the air-line C, a method which has been found to be effective and economical. The mixing chamber Dis preferably constructed of porcelain. A steel shell lil supporting a relatively thin porcelain cylinder D packed against the steel backing with silicate of soda and silex cement is suitable. The porcelain mixing chamber; l) is grilled with quartz packing ln and has an internal diameter of twelve inches (12) and a length of not much more than live feet. Diluting water is introduced through the conduit` G which is preferably constructed of the material known as duriron. enters the mixing chamber l) through the pipe H, which, through the porcelain nipple I communicates with the interiorly lined duriron tube J. The upper part of the mixing chamber is closed by the lead top K, suitably apertured for the acid tube J and the water tube Gr. The strong acid and the diluent, as well as the cooled product from A. are continuously fed into the mixing chamber, in regulated volume, and the diluted product flous from the bottoni ci? the miv.-

The strong acid Cil ing chamber D into the bottom of the product cooler A through the connection L In the apparatus as described l have produced 93% sulfuric acid from 98% sulfuric acid at the rate oi about 60 pounds perk ininute for which l required a mixtuifeioi approximately 90 pounds or" iinished product and the necessary amount of 98% acid and of Water. l

The surplus of finished product, in excess of what is required for storage and circulation in the apparatus as thus far dc- Scribed, .is Withdrawn through the pipe M.

linstead of mixing the strong acid and the cooled product and subsequently introducing the Water, all three may meet at thc same point or the strong acid may be mixed 'with Water and very slunrth` thereafter .tloiv into the circulating body ot cooled product. lt is-best in any case to employ all three ingredients in the -form of streams moving concurrently.

Cooled finished product is the only inaterial. available to be introduced into the strong acid for its dilution ior absorption o1E the heat due to the diluting action and to prevent undue rise of temperature with its accompanying disadvantages, interruptions and defects; and it makes but little difference to the effectiveness ot that cooling, in what order these three things are brought together.

Although the invention has been described with particular reference to sulfuric acid, the invention may be of use for application in other diluting operations, involving other substances that present the :same problem, and it is intended that. the

claims, although in terms of sulfuric acid, shall include equivalents. Y

lt Will be noted that the procedure cmployed by me differs from staiulard practice mainly in preventing any deleterious heat of dilution from coming vinto being, Whereas, according to the old practice, the .heat of dilution was continuously created and attempted to be continuously withdrawn through the cooling coils. According to the new practice, the injection of a cooled body of finished product into thc strong sulfuric acid when it is mixing or is about to mix or right after it has mixed with the Water (the last two being adjusted in volume to make the desired finished product) serves to maintain the temperature of the mixed material at or below the temperature of the strong acid to be diluted and produces a finished product which does not possess a temperature rendering i. injurious to appa.- ratus. By cooling the outliow from the mixing charilier and returning a part of this cooled product to the diluting vessel, it is enabled to act as a heat absorber, which functions so that there is no temperature rise of consequence when dilution takes place. The process functions continuously in exceedingly simple apparatus, the mixing device is very compact, the area o't excessive corrosion is greatly reduced, an accurate control is possible and rapid replacenient with repair .pai'ts,should-such...re-nY placement be necessary, can easily be made.

llhat l claim is:

l. ln the art. of diluting' sulfuric acid, that improvement which comprises cooling a product or' dilution at a point remote from the point of dilution and then feeding the thus cooled product to the point where dilution takes place.

2. ln the art of diluting sulfuric acid, that improvement which comprises setting up in a product ot dilution a reduced temperature of such degree as to enable the difference between the reduced temperature and the normal temperature Which the product would possess but for the said reduction oi" its temperature to absorb the heat of dilution produced by bringing together strong acid, a diluent and such cooled product 01"' dilution.

8. In the art of mixing sulfuric acid and a diluent, the improvement which comprises cooling a body of finished product and bringing such cooled finished product into ahsor ing relation with strong acid and a dilucnt to maintain the temperature of the mixed material at or below the temperature of the strong acid to be diluted.

4. In the art of diluting sulfuric acid, the process which comprises co-mingling strong sulfuric acid, a diluent and a pre-cooled body of finished product, so.-that the 'temperature of the Whole co-niingled material maintained below the temperature of destructive action upon materials oi" construction oi" the mixing' chamber. y

5. In the arl. ot' diluting sulfuric acid, the process which comprises cooling a product of dilution at. a point remote from the point of dilution., continuously feeding a portion of said cooled product of dilution to the point of dilution, and in thc. region of said point ot dilution adding strong acid and Water, returning the product of dilution thus produced to the region where the product of: dilution is cooled and continuously withdrawing from the accumulating product of dilution the excess or"v such product over the amount thereof required for the maintenance or a proper storage supply in the system and of the requisite circulation of said product.

ln testimony whereof l have hereunto set my hand. 

